CELL DEATH IN RETINAL DAMAGE INDUCED BY COMMERCIAL LIGHT EMITTING DIODES (LED)
Résumé
Spectra of “white LED” are characterized by an intense emission in the blue region of the visible spectrum, absent in day light spectra. This blue component and the high intensity of emission are the main sources of concern about the health risks of LED with respect to their toxicity to the retina. In this work we used commercially available white LED and four different blue LEDs (507, 473, 467 and 449 nm) to expose Wistar rats for 6 hours to 3 days. We evaluated LED-induced retinal cell damage by studying oxidative stress, stress response pathways and the identification of cell death pathways. LED light caused a state of suffering of the retina with oxidative damage and retinal injury. We observed a loss of photoreceptors and the activation of caspase independent apoptosis, necroptosis and necrosis. Necrosis being the mayor pathway of cell demise. A wavelength dependence of the effects was observed: blue LED being more toxic. Moreover, we show here, once again, that different markers of cell death need to be used in order to prove the toxic effect of light.